A Micro-Nano Fiber Bragg Grating Refractive Index Sensor

Abstract

The invention discloses a novel micro-nano optical fiber Bragg grating refractive index sensor, which includes a broadband light source, an optical coupling element, a micro-nano optical fiber Bragg grating connected in sequence, and a wavelength detection unit connected with the optical coupling element; The optical signal emitted by the broadband light source enters the micro-nano fiber Bragg grating after passing through the optical coupling element, and after being reflected by the micro-nano fiber Bragg grating, it passes through the optical coupling element again to enter the light wavelength detection unit; the micro-nano fiber Bragg grating The grating has a plurality of high-order harmonic reflection signals, and the sensitivity difference of each harmonic reflection signal wavelength to the environmental refractive index is different from their sensitivity difference to the environmental temperature, so that simultaneous measurement of the environmental refractive index and temperature can be realized. The novel micro-nano optical fiber Bragg grating refractive index sensor of the present invention has the advantages of compact structure, low cost, high manufacturing efficiency, reduced effective bandwidth occupation and simple implementation method.

Description

technical field [0001] The invention relates to the research field of optical fiber grating refraction sensors, in particular to a novel micro-nano optical fiber Bragg grating refractive index sensor. Background technique [0002] With the advantages of low cost, flexible structure, biocompatibility, electrical insulation, and remote measurement, optical fiber biochemical sensors have developed rapidly in recent years. [0003] The optical fiber evanescent field biochemical sensor uses the evanescent wave generated by the light wave at the interface between the optical fiber and the external environment to feed back the specific biochemical reaction information on the surface of the optical fiber to the optical transmission signal through the change of the refractive index. Therefore, as long as the optical signal parameters Tracking enables label-free detection of biochemical quantities. This detection method is only related to the concentration of the analyte and does not...

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Problems solved by technology

However, this method has the following problems: 1) the use of rectangular cladding fiber will inevitably lead to the increase of cost and the compatibility of the transmission system; The ability to distinguish parameters, and increasing the birefringence will further expand the initial wavelength difference of the reflected signals in two orthogonal polarization directions, thus occupying more effective signal bandwidth, which is not conducive to future multi-parameter measurements based on wavelength division multiplexing systems development needs

Since the refinement of the optical fiber will cause a large blue shift of the Bragg resonance wavelength, the high-order mode coupling signal at the traditional design wavelength will appear in the "water absorption" region of the optical fiber, causing problems such as a decrease in the signal-to-noise ratio or even annihilation of the signal.

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